Patients of the Lifeworks service, based in Cambridge, say the closure will lead to greater self-harm and social isolation in the community.

Lifeworks is part of the trust’s Complex Cases Service for people with personality disorders, which is to be axed in favour of a countywide system of GP referrals due to budget cuts.

But users of the centre say its loss will leave them isolated and vulnerable.

Supporters spent two hours in Ely’s Market Place on Saturday talking with shoppers. More than 500 signatures to a petition opposing the closure were collected in under two hours.

Campaigners were joined by Huw Jones, Labour parliamentary candidate for South East Cambridgeshire.

He said: “I’m worried that the closure of Lifeworks is a false economy. This is a county-wide service that concentrates on support and prevention. If it closes, then service users are likely to present at hospitals and A&E, needing more intense, expensive interventions.”

Alex Jones, 34, who uses the service, said: “There are going to be a lot of people with serious mental health problems left with no support at all at the end of this month when there is no drop-in centre for their needs in the whole of Cambridgeshire.

“It costs £18 an hour for a private session with Mind and people are not going to be able to afford that.”